The basic principle of the invention to be described is believed by the inventors to be wholly original in the sense that what has been achieved uses an A.C. excitation technique which interposes capacitors in a thermocouple circuit. The operation is in A.C. mode, even though the electrical power supplied to or by the system can be D.C. or A.C. The inventors have no knowledge of any prior disclosure which is based on the conception that a thermocouple device can operate by current passage through the junctions in a sustained A.C. mode. Indeed, the normal expectation of such a proposal would be that the cyclic heating and cooling of each thermocouple junction at the operating frequency should have no advantage for energy transfer and should merely generate ohmic loss and lose heat by thermal conduction.
Concerning the effects of a magnetic field on thermocouple operation, a subject which arises in describing certain aspects of the invention, the inventors are aware of experiments where the effects of magnetic fields are used to measure the Nernst effect, for example. In these experiments thermocouples are used to measure temperature differentials in the presence of strong magnetic fields. However, none of the scientific papers seen by the inventors discusses any anomalous effects of the magnetic field upon thermocouple operation. Bearing in mind that instrumentation techniques based on galvanometer measurement using direct current often rely on a minimal current flow by using balancing potentials, it is conceivable that certain effects occurring when alternating or significantly high current densities flow through thermocouple junctions subjected to magnetic fields have not hitherto been researched. In these circumstances, though the primary invention in its broadest concept is not concerned with the interaction with magnetic fields, the scope of certain aspects of the invention to be disclosed extends in this direction.